Aromatic high softening point petroleum resins and process for its preparation

Abstract

High softening point, i.e. greater than 140 DEG C., aromatic petroleum resins are prepared by polymerizing with an AlCl3 catalyst an unsaturated hydrocarbon mixture of one part of (1) a feedstock fraction obtained from the thermal cracking of petroleum boiling in the range of 135 DEG -220 DEG C. and principally composed of aromatic substituted olefins, e.g. styrene and its derivatives and indenes and its derivatives and from 0.3 to 1 part by weight of (2) oligomers of cyclopentadiene.

What is claimed is: 
     
       1. A process for preparing a high softening point resin which comprises polymerizing in the presence of at least a catalytic amount of aluminum chloride, an unsaturated hydrocarbon feedstock mixture in the ratio of: one part by weight of (1) a vinyl aromatic stream having a boiling range of from 135° to 220° C. and which comprises from 3% to 10% styrene, from 2% to 6% α-methyl styrene, from 15% to 25% vinyl tolune, from 10% to 18% indene and from 4% to 12% methyl indenes; and from 0.3 to 1 part by weight of (2) oligomers of a cyclopentadiene stream which comprises 0.5 to 6 wt.% butadienecyclopentadiene, 2 to 8wt.% isoprene-cyclopentadiene codimer, 25 to 40wt.% dicyclopentadiene, 3 to 10wt.% piperylene-cyclopentadiene codimer, 25 to 40 wt.% cyclopentadiene-methylcyclopentadiene codimer and 2 to 8 wt.% methylcyclopentadiene dimer; (b) quenching said polymerized hydrocarbon feedstock mixture to remove catalyst residues; and (c) finishing the washed polymerizate to provide a petroleum resin having a softening point of about 140° C. to about 160°  C. 
     
     
       2. The process according to claim 1 wherein said aluminum chloride concentration ranges from 0.3 to 3.0 weight percent based on the total weight of the mixture and the polymerization is at a temperature of from 0° to 60° C. 
     
     
       3. The process according to claim 2 wherein the polymerization is continuous with a reaction residence time of from 0.05 to 2 hours. 
     
     
       4. The process according to claim 1 wherein the polymerization is batch and the aluminum chloride concentration ranges from 0.2 to 5.0 weight percent based on the total weight of the mixture and the polymerization is at a temperature of from 0° to 60° C. and is maintained for a period of 1 to 2 hours. 
     
     
       5. The process according to claim 1 wherein said polymerizing is batch and said aluminum chloride concentration ranges from 0.2 to 5.0 weight percent based on the total weight of the feedstock and said polymerizing is at a temperature of from 0° to 60° C. and for a period of one to two hours. 
     
     
       6. A high softening point petroleum resin prepared by a process which comprises (a) polymerizing in the presence of at least a catalytic amount of aluminum chloride, an unsaturated hydrocarbon feedstock mixture in the ratio of: one part by weight of (1) a vinyl aromatic stream having a boiling range of from 135° to 220° C. and which comprises from 3% to 10% styrene, from 2% to 6% α-methyl styrene, from 15% to 25% vinyl toluene, from 10% to 18% indene and from 4% to 12% methyl indenes; and from 0.3 to 1 part by weight of (2) oligomers of a cyclopentadiene stream which comprises 0.5 to 6 wt.% butadiene-cyclopentadiene, 2 to 8 wt.% isoprene-cyclopentadiene codimer, 25 to 40wt.% dicyclopentadiene, 3 to 10 wt.% piperylene-cyclopentadiene codimer, 25 to 40 wt.% cyclopentadiene-methylcyclopentadiene codimer, and 2 to 8 wt.% methycyclopentadiene dimer;   (b) quenching said polymerized hydrocarbon feestock mixture with a water/isopropanol solution and thereafter washing it with water; and, (c) finishing the washed polymerizate to provide a petroleum resin having a softening point of about 140° C. to about 160° C. and a styrenes/indenes/oligomers molar ratio ranging from 0.5/0.4/1 to 3/1/1, respectively.   
     
     
       7. The resultant polymer according to claim 6 wherein said molar ratio ranges from 1.4/1.9/1.0 to 1.0/0.8/1.0, respectively.